blood r



Aug. 28, 1956 H. L. BLOOD Re. 24,202

INTERNAL GRINDI'NGVMACHINE AND METHOD Original Filed Aug. 16, 1951 10 Sheets-Sheet 1 Aug. 28, 1956 H. L. BLOOD INTERNAL GRINDING MACHINE AND METHOD 10. Sheets-Sheet 2 Original Filed Aug. 16. 1951 Aug. 28. 1956 H. BLOOD 24,202

Y INTERNAL GRINDING MACHINE AND METHOD Original Filed Aug. 16. 1951 10 Sheets-Sheet 3 i v 1 1a Aug. 28, 1956 H. L, BLOOD Re; 24,202

INTERNAL GRINDING MACHINE AND METHOD Original Filed Aug. 16, 19 51 10 Sheets-Sheet 4 Wdffiili Aug. 28, 1956 HHL. BLOOD INTERNAL GRINDING MACHINE AND METHOD 10 Sheets-Sheet 5 Original Filed Aug. 16, 1951 Aug. 28, 1956 BLOOD Re. 24,202

INTERNAL GRINDING MACHINE AND METHOD Original Filed Aug.-l6, 1951 losheets-sheet a Aug. 28, 1956 H. L. BLOOD INTERNAL GRINDING MACHINE AND METHOD l0 Sheets-Sheet 7 Original Filed Aug. 16. 1951 Aug. 28, 1956 BLOOD Re. 24,202

INTERNAL GRINDING MACHINE AND METHOD Original Filed Aug. 16, 1951 10 Sheets-Sheet 8 Aug. 28. 1956 H. L. BLOOD Re. 24,202

INTERNAL GRINDINGMAC HINE AND METHOD Original Filed Aug. 16. 1951 7 l0 Sheets-Sheet 9 Aug. 28, 1956 H L, SL0 5 Re. 24,202

INTERNAL GRINDING MACHINE AND METHOD Original Filed Aug. 16, 1951 10 Sheets-Sheet 10 v INVENTOR 2 10020 2.9 000 Re. 24,202 -Reissued Aug. 28, 1956 United States Patent Office GRINDING: IMETHOD Harold L. LBlood, Worcester,

assignments, to The poration' of Delaware Mass, assignor, by mes'ne Heald "Machine. Company, acor Original No. 2,646,652, dated -Julyv28, 1953,:SerialrN0:

.242,102,-August.-z16, 1951. Application for ,February 24, 1954, Serial. No.. 412,407

41 7 Claims. (Cl.-51 '103) :reissue- Matter. enclosed in--heavy brackets-[ appears in the original patent but forms .noapart of .this :reissuespecifi cation; matter printed in italics indicates ..the.addit ions.

made by reissue.

Thissinventionrelates to internal-grinding machineseof the centerless or chuckless type, ,in which =workpieces-are guided by their preformed outer'surfaces of revolution while being rotated, and plied torefine internal surfaces of revolution-intheworkpieces.

.One difiiculty with such machines is that in -practice,-

' between the plate and work is high, it being'zwell-known I some irregularities produced :by previous operationsgare present-omthe outerguide surface of a workpiece and a rotating wheel ,ortoolisiapthese irregularities adversely affect the accuracy tof the al. ;patent the workis held in contact with a fixed roll and However, in the Einstein-ct being generated, and are repro v workpiece-is held against an end stop the linecontact between the convex surface of the roll and theconvex surface of the Work cannot bridge irregularities in the outer surface of the work. These irregularities wi1l,:therefore, be reproduced, at least in part, in the inner surface being. ground. Further, differences in the outer diameters of successive workpieces willaffect the '5 diameter of theinner surface. shows'the work heldtagainst a have foundit difficult to rotate using this; principle. the present invention.

As-apart of the .present invention, the effect :on the The Einstein et a1. patent stationary end stop -.-and' I the work smoothly avhenw All-these diificulties are avoided in Work against both the work inner surface of irregularities in the outerasurface isminimized by'holding this outer surface against a stationaryconcave shoe or support surface which-substantially conforms with. the outer surface and .extends circumferentially in contact therewith suificiently' to bridge irregularities therein and to fix thecenter of rotation of the .rotating workpiece.

It ,is highly desirable to locate this support .Is'urface, with-'respect to the line. of contactbetween toolandwork} sothat variations .in-the outer diameters of successive workpieces will'havea comparatively small efie'ct-on thediameters of their inner-surfaces. Otherwise, the'manufacturingtoleranceon the outer diameter would 'add-to the variations in inner diameter which would "be "pro duced'by the finishing operation;

As another feature of the invention, 'thesupport sm face is, therefore, so locatedthat the centers of work pieces having different outer diameters 'fall in a line'sub stantiallyat right angles tothe direction of radial feed motion of the Wheel. The'lsupport surface extends 'ap proximately'thesame .distance on either side of a line through the center of the work normal to a line'through; the centers of the work and tool. With this arrangement,

two-or more workpieces may be finished simultaneously byethe' same; tool toathesame inner diameter within a close tolerance.

If the supportisurface is located below the work and the tool is fed horizontally, the wheel tends-to lift the :work out'of'the-suppo1t. This lifting must be prevented, but it is also desirable at frictionibetweenzthe'i work and support; It wouldiotherwise be difiicult to rotate the-work :byfriction means, and exeessive wear'ofathea support! WOllldiOCCUI'; The, present I invention includes means for holding the the-support withoutexcessive friction.

It wouldbe-rpracticable to rotate .thework in theisupport bypressingaface of the Work: against a backplate rotating on a fixed axis, and ithas been-customary tolocate=such-- a plate eccentric with respect-tonthe -'-work, "in a direction which insures against lifting the work-:aWayfrom-the,support." -.Bu-taans eccentric driving plate hasthedisadvantage of :incr'easing-ethe rfriction between work: and support and increasing the wear on both the supportandthe-plate' lhetpresentrinvention 1 includes end. stop 'means comprising a back plate which is free to rotate on an axis determined by the work, and-LWhiCh fixes-the planeaof the face of the work? accurately. Since there is no slip'pagebetween-athe-:plate and-the work, the coeiii'cient .of friction that thet-friction 'ofr restis ordinarily higher than the friction oft-motion."

The-:high co'eflic'ient of.--friction means that-a comparatively small force is sufiicient to hold the work zagainstxthe rotatingplate and thereby to rotate-thework. The present invention,:therefore, plying-anaxialforce against one face .of the work,to press a pair ofwskewed workq-atnearly opposite suffi'cient axialforce. Such .an arrangement-permits the wheelhead-to be brought close to the work, since there parts. Thelen'gthof the wheel spindle: may thus be reduced to a minimum, whichis often needbe no intervening a great advantage in internal grinding;

-When -rolls :are pressed against the periphery of v the workiti's essential-that they donot disturb-the work-in Means are, therefore, provided :to insure the zsupporti thzit-equal-f'force is exerted upon the work by opposite rolls.--

The; samepressuremeans support means and the back platewor other-end stop means. Itis importantto note, howevenwthae-suchpressure means are not fixed-and do not in themselves locate, the work butirather serve to .urge theiwork againstthe work-locating means;

vIt is alsoimportant to note that the'problemspresented' in int'ernal-center1ess grinding with which the present inventionis concerned, are quite different from those'of external .centerle'ss-grinding.

In external grinding ,problems; a very large wheel mounted-on 'a-.heavy.spindle maybe used so that spindle" defiectionzandwheel-:wear problemsare not acute. The works'is supported onthe same surface which-is being ground or at lleastanother external: surface and the means ,forxlocati-ngsand rotating. the work:ean be arranged quite diiferently-with relation to the wheel than is the-case in internal grinding and such arrangements are :at least unsatisfactory and usually vuseless-in connection with-linternalgrinding.

lniinternal grinding, since the grinding ,wheel ortool must lac-introduced insideofa comparatively small bore, the Wheel .is .muchsmaller than an external type-wheel and in order .to reach .into the work it must be mounted on a comparatively .long and thin fspindle. "Therefore, spindle deflec'tion the Work,"

the same time to preventhigh Work against makes'it possible, insteadvof 2113- rolls-againstthe periphery of the points and in, this way towdevelop' 'rnaybeusedboth to hold the problems arise causingfinaccuracies 'in particularly if the "woi'lclocatin'g' and support means prevent reduction of spindle length to a minimum. The present invention is concerned, therefore, not only with means for locating work by its external surfaces while finishing an internal surface, but also with the means in combination therewith for rotating the work and for holding it against the locating means and at the same time allowing application of an internal finishing tool which has as short a spindle as possible.

In the drawings:

Fig. 1 is a partial'front elevation of a machine of the invention. i

Fig. 2 is a view similar to Fig. 1 with some of the parts broken away and others in section. 1

Fig. 3 is a right end elevation of the work support arrangement.

Fig. 4 is a plan view of the work support arrangement.

Fig. 5 is a section on line 5--5 of Figs. 2 and 9.

Fig. 6 is a section of a modification of the work support means taken on line 6-6 of Fig. 7.

Fig. 7 is a right end view of Fig. 6.

Fig. 8 is a plan view of Figs. 6 and 7.

Fig. 9 shows another modification viewed in section.

Fig. 10 is a partial right-end view of the embodiment shown in Fig. 9.

Fig. 11 is a plan view in section of a further modification.

Fig. 12 is an end view of Fig. 11.

Fig. 13 is an end view of another modification.

Fig. 14 is a side view of Fig. 13 partly broken away and in section.

Fig. 15 is an end viewof a further modification.

Fig. 16 is a side view of Fig. 15 partly in section.

Fig. 17 is an end view of driving means for the modification of Fig. 16.

Fig. 18 is an enlarged and exaggerated partial end view of a workpiece seated against a support shoe.

Referring to Figs. 1 and 2, the machine includes a is fastened a bridge 4. A grinding tool 6 is carried on a spindle 7, the designation grinding tool or wheel being used herein to cover the usual internal grinding wheel comprising bonded abrasive material or the more recent metal tools such as burrs, that is, cylinders of tungsten carbide or other hard material having fine cutting teeth thereon which are adapted to serve the same function of finishing an internal surface to close tolerances. The spindle 7 is journaled in a wheelhead 3 on the bridge. A dressing or truing tool is indicated at 188. The wheelhead 3 is mounted on a slide 2 which slides on ways on the bridge 4 to provide transverse or cross feed of the wheel 6.

Referring also to Fig. 3, an annular workpiece 8 rests on a work support 9, which is adjustably mounted on a body-10 carried by the table 1. The support 9 has a concavesupport surface 921, preferably faced with tungsten carbide or other wear-resisting material, which substantially conforms with work and extends circumferentially in contact with the periphery sufiiciently to bridge irregularities therein and to fix the center of rotation of the work. Fig. 18 shows the irregularities 8a exaggerated on the periphery of the workpiece 8, and how the shoe surface 9a bridges across them. Such irregularities, for instance those produced by a comparativelyrough machining operation as compared to a finishing operation on the workpiece periphery result mostly from tool chatter and average about equal in height and depth between a maximum workpiece radius-R1 and a minimum workpiece radius Rz. It is seen that since the support surface 9a rides tangentially across the peaks of the irregularities, no movement of the work results such as occurs when the work is supported by a blade or roll type support which produces a line contact with the work causing the workpiece to move on its support as the line contact rides up and down over the irregularities. The support 9 is shown relieved to the preformed periphery of the insure contact with the work near the ends of the support. In many applications a continuous support is satisfactory particularly where uniformity of outside workpiece diameters is to be expected, but it is preferable to divide the work support 9 as shown because an undersized workpiece has a tendency to rock in a support having a continuous surface whereas a divided surface pro vides a saddle which serves to maintain in fixed radial position successive workpieces which vary slightly in outside diameter. This invention, however, covers the use of both continuous and divided concave workpiece support surfaces. be seen that the support surface 9a is concave circumferentially of and in a plane normal to an axis A. Since the support surface may, for certain purposes, not always be circular as shown, it may have more than one axis. Such multiple axes as well as the axis A may, for practical purposes, be designated as the average axis of the support surface.

" sheaves 17 and 18 which smaller than the sheaves down in contact table 1, arranged to reciprocate on a base S-to which 3' A The workpiece 8 is rotated in the support 9 by rolls 11 and 12 which engage the periphery of the work. The rolls 11 and 12 are journaled in arms 13 and 14 fulcrumed on studs 15 and 16 in the body 10 and are driven by are connected to the rolls by the arms 13 and 14. on a drive motor 21 shafts, not shown, running through A belt 19 driven by a sheave 20 passes over an idler 22 and around the sheaves 17 and 18 to drive them. The sheaves 18 may be made slightly 17, the difference being exaggerated in the drawings, so that the surface of the roll 12 moves downward in contact with the work 8 at a higher speed than the surface of the roll 11 moves upward in contact with the work, tending to hold the work with the support 9. The rolls 11 and 12 may be journalled, as shown, slightly above the center of the work to aid in holding it down.

Tension in the belt 19 tends to swing the rolls 11 and 12-so that they each exert a force on the work, these 1 opposite forces being substantially equal since the difference between the diameters of the sheaves 17 and 18 is slight and may be compensated for by suitable arrangement of the angles formed by the belt 19. Additional forces between the rolls 11 and 12 and the work 8 are provided by a spring 23 which pulls on the arms 13 and 14 with equal force. This balancing of pressures is important to prevent the work from being pushed away from the position in which it is located by the support 9.

The rolls 11 and 12 are skewed, as best shown in Fig. 4 the direction indicated by the arrows they hold the work 8 against a cup shaped back plate 24 as well as holding it down in the support 9. This is due to the fact that when the rolls are skewed and rotated as shown, they exert a component of force on the workpiece which is axial and toward the back mounted on the backplate backplate 24in a substantially concentric relation to the workpiece 8 is pressed against the backplate 24 and ro-' tated, the work drives ing on an axis determined by the work and compressing the springs 56 as necessary.

bore of the body 10 when no work is present. When a the plate by friction, the plate turn- The backplate 24 accurately fixes surface of work held against it. relatively short in an axial direction so that it will not the plane of the end interfere with the fixing of the plane of the end surface by the backplate.

By further reference to Figure 18 it will position, being pro- The support 9 is shown Wi h this combination of s pport and backplat an its arrangement with respect to the .Wheel 6, .theiinner surface of a workpiece may be ground on an axis precisely at.

right angles to an end surface and concentric with the periphery in at leastone plane, and a succession of workpieces having slightly diiferent outer diameters maybe ground to substantially the same inner diameter" Finished work may be ejected by an ejector plate 25.

pushed by any desired means such asa piston rod 26 and piston 27 in a cylinder28 whent a valve 60,, Fig. 4, is turned manually, or by any desired means to admit fluid pressureto the'left end of the cylinder-J8. As therqd.

and. an arm 35 releases with incined surfaces 39,.and 40 'onthel link 30, rocks ,an escapement lever .31. in a clockwise direction so that anarm 32 blocks the fall thesupport 9 wh n the levers 13rand;14 to push .these levers apart, swinging the.

'away from the workpiece to perrnitiejecrolls 11 and 12 tion thereof.

The principles of the support arrangement which has.

been described may be utilized in grinding two or more workpieces simultaneously to the sameinn'er diameter, since manufacturing tolerances on. the outer. diameter move the center of the work at right anglesto the'direction of feed and so have negligible effect on the inner diameter. Such an arrangement is shown in Figs. ,6, 7 and 8.

In this embodiment two workpiecesfland 8 are shown 1 against a backplate 24". In this resting in a support 9 case the support 9' is axially long enough to sea than one workpiece.

Skewed rolls .11 and 12 carried in 23, and rolls 11' 14 are urged against the work 8 by, a spring 23. These rolls have the same effect as previously describedinholding the'workpieces down against against the backplate 24'.

Holes as shown at 96, 97 and 97 each work locating surface of the support 9' and connected to a supply line 95. Air or other fluid may be introduced under pressure through the line 95 ,to reduce the contact pressure between the work '8 and,8 and the support 9, lowering the friction which might otherwise prevent the work from rotating freely in the support.

The work may be rotated either by,the rolls which are driven as shown in Figs. 1-4, or by the backplate. In order that both embodiments maybe illustrated, abackplate 24 is shown in Fig. by a belt 19 and motor 21,

the supp r and als desired, but not essentially, center of the backplate 24 may be located slightly to the left of the center of the work in Fig. 7. This eccentric mounting also tends :10 hold the work down in the support 9 when the backplate 24'. and work 8 rotate in the direction of the arrow. However, because the rolls are usually suflicient-to'hold the work down on the support, it is to mount=the backplate concentrically withtbework in order that there be no sliding between them, the friction of rest allowing the backplate to exert greater rotative force on the work when the backplate'is used to drive the work.

Rolls 43 and 44 are the'workpicces 8 and 8 the wheel 6 may be fed without lifting the work and 44 are each carried behind the other in Fig.

against the work with great-force out of the support 9.

on a lever45, one of which. is 6. Thelevers 45 are pivoted .at

41 and each carries a pin .49. contactinga carnor wedge surface 48 on one of the. ;sliding.bars 50. and 51. which toward theleft, causing. therolls are urged by springs 52 43 and 44 to beheld against the workpieces 8 and 8.

maybe provided in 6 carrying asheave..42 driven Fig. 8. The backplate 24"1is mounted on anti-friction bearings 57 in thebody lt). If

ordinarily preferable arranged -to bear each on. one. .of near the top of the work, so that V levers 1-3 and 14 are urged againstthe work 8 by a spring and 12' carried in similar levers 13 and .The spr nssfiljm v compa e y ht tho ium-5 surfaces. 48 into position to resist upward movement of the work and rolls and tion being to move the cam without creating excessive friction between the workand support 9. Theangle ofthe cam or wedge-surfaces .48

maybe so chosen that when rolls .43 and .44 move downward they will exert a force quired to move them upward, in fact, these cam or wedge surfaces may be made irreversible. It will be seen that similar .results may be obtained with any .type .of cam.

surf ce including screw threads.

For loading, fluid end of. a cylinder.28 by I .pushinga piston assembly 29'to the right.

assembly 29 pushes theybars 50'and 51 to the right compressing the springs '52 and movingthe cam surfaces 48 away from the pins .49, allowing. the; levers to'be; raised1by the springs 6l,1l ifting,the rolls A3 an d 44 clear of the work.-

On eachbar and 51 which, when the bars. are viewed in Fig. 6, push pins and.14 moving the rolls 11, 11, 12 and 12 manuallyand replaced by unfinished work. the backplate 24'.Wlll rotate the workpiece 8' against it and. workpiece 8' will rotate the workpiece}.

The rotation of the ,workwill rotate the skewed rolls'll; 11', 12 and 12 which engagethe work and the rotation" of theserolls forces the. work against the backplate.

In another embodiment of this invention,"illustr'ated in'Figs. 9 and 10, the work18 may be held againsta driven backplate 24. j by two rolls 64 end surface of the work at its line of contact withieach of the rolls.64 has a small upward component, that is,

the work must slide upwardly across each 'ro1l,jsince the...

surface of the roll moves horizontally, producesa downward force on the work.

The rolls. 64 are. carried by a yoke v65 ona bar 66 fastened in ablock 67 fulcrumed at and this sliding pressure means, such as a fluid cylinder 70, to force the rolls,64 against work 8. A spring 71 swings,the bar 66 to separate the rolls 64 from thework when pressure is I released from thecylinder Jt'o permit loading.

The backplate 24 located axially, but not radially, bearing 54". Theweight of the backplate 24'."is taken on spring pressed pins 55 as shownin Figs. '2 and, 5

engagingasurface 57 on a race of the bearing,54" and holding the backplate substantially concentric with thef support 9", except when moved away from this locatio n by the work.

The backplate 24" is shown in Fig. 9 driven by a sheave .72 which rotates on a ball bearing 73 carried on a bushing 74 on a cylinder 75 mounted on the body. 1 0.' The sheave 72 is rotated through a belt.and amo'tor.

not shown, and has internal splines [gear teeth] 76 which drive one end of a floating gear 77, the other end of which drives the backplate 24" by internal splineslgear teeth] 78 therein. I

This construction allows the backplate 24" work held against it, without tending to movethe. work away from its center of rotation as fixed by the sup, port 9". Since. there is no sliding between the work, ,and.. the plate, the coefiicient of friction.is. high;.and.wear,is

minimized.

When the rolls 64 are swung away from thework as.

has been described, the work may be ejected conveniently much smaller thanJthatrepressure may be admittedtothe; left a manually operated valve "60 Thepiston are two inclined'surfaces 62' pushed toward the right ,63' against arms'13,1'3', 14 away-= from the work. The finished work may now be removed? Rotating pressed which .engage an end' surface of thework. j The axes-of therolls 64 are offset this oifse'tis toward the. the work is rotated. by

against the '68 in a'bracket 69- attached to the body..10. The bar 66 may be swung by is mounted as shown in Fig.2 being. by a flatplate .ball'thrust to drive.

to the left end of the cylinder rod 26", ejector plate 25" and by applying fluid pressure 75 pushing a piston 27", work 8 toward the right.

In another embodiment, shown in Figs. 11 and 12, rolls or discs 100 are provided to engage an end surface of the work 8 and to force the work against a revolving backplate 101. With [By making] the rolls 100 made comparatively thin [discs] and [by placing] with their axes at an acute angle to the axis of the backplate, as shown, or parallel to the axis of the backplate, it is possible for the wheelhead 3 to approach the work 8 closely, minimizing the length of the overhung portion of the wheel spindle 7.

The support shoe 9 may be located as desired, but it is shown so located as to provide support for the Work directly in line with the direction of feed.

One of the rolls 100 may be driven by a belt on a sheave 102 in a direction to urge the work against the support 9 or the backplate 101 may be driven by a belt on a sheave 103, or both driving means may be used.

Each of the rolls 100 has a stem in a sleeve 10% which is journalled in bearings 104 in a housing 105. A spring 107 in each sleeve 10% pushes against the hubs of sheave 102 and sleeve 100b, urging the rolls 100 against the work. Housings 105 are connected by a plate 106.

Another modification is shown in Figs. 13 and 14 in which the work is located radially both by a fixed concave support 209 and by a radially fixed but rotatable solid slow roll 215 on a shaft 217 which may be driven as by a pulley 216 on the opposite end of the shaft 217. The work 208 is urged against the fixed support 209 and the roll 215 by a pressure roll 220 on a spring urged arm 221. The fixed support 209 is located to support the work in line with pressure from the grinding tool 206. The work 208 is supported axially by a backplate 240 similar to others herein described. Either or both of the rolls 215 and 220 may be skewed to force the work against the backplate 240. A driven backplate may be substituted for drive means for the roll 215 in order to drive the work 208.

A still further modification of the invention is shown in Figs. 15-17 in which a workpiece 308 is held by a pressure roll 320 which may be skewed, mounted on a spring arm 321, against a fixed concave work support 309 of the type previously described herein. The workpiece 308 abuts against a backplate 324. A permanent magnet 325 is mounted in the backplate spindle 326. The fixed support 309 is comprised of non-magnetic material such as boron carbide. by the pressure roll 320 or by the backplate 324 or by both, as illustrated, through pulleys 322, 327 and belts 328, 329 connected respectively to a drive motor 330, as seen in Fig. 17. The magnet 325 establishes a magnetic circuit including the backplate 324, the workpiece 308 and the pressure roll 320 thus increasing the friction between the-workpiece and the parts which drive it, and improving the characteristics of the means for driving the workpiece 308.

lt will be seen that the backplate provides end stop means which in all cases has work engaging elements circularly arranged around and in a plane which is substantially normal to the average axis A of the support shoe, and that in the case of an eccentric backplate, these supportelemcnts are concentric to the backplate spindle axis and slightly eccentric to the average axis of the suppo r'tsurfac'e. It will also be seen that while the work engaging elements comprising the face of the'end stop means are arranged to abut the end of a workpiece and hence to fix its endwise position, the contact with the work" is solely in a plane substantially normal to the average axis and therefore the end stop means does not exert a centering action on the workpiece but allows the workpiece to be supported radially solely by the support shoe-or shoes.

100a slidably mounted The workpiece 308 may be driven either r 8. I claim: [1. In an internal grinding machine for refining an inner surface of revolution of a workpiece, said workpiece having an outer preformed surface of revolution, and in combination, means to rotate the workpiece, fixed work support means having an arcuate concave surface generally conforming with said outer preformed surface and extending circumferentially in contact therewith sufficiently to bridge irregularities thereon and to position the rotating workpiece radially, a grinding tool applicable to said workpiece to refine said inner surface, rotating end stop means abutting the workpiece preventing its axial movement in one direction, and pressure means independent of said end stop means engageable against and located by the workpiece to hold it against said support means and against said end stop means] [2. In an internal grinding machine for refining an inner surface of revolution of a workpiece, said workpiece having an outer preformed surface of revolution, and in combination, fixed work support means having an arcuate concave surface generally conforming with said outer preformed surface and extending circumferentially in contact therewith sufiicient to position the workpiece radially, a grinding tool applicable internally of said workpiece to refine said inner surface, rotating end stop means abutting the workpiece preventing its axial movement in one direction, yieldably mounted roll means engageable against said outer surface holding the workpiece against said support means, means to urge the workpiece against said end stop means, and means to rotate the workpiece in said support means] [3. In an internal grinding machine for refining an inner surface of revolution of a workpiece, said workpiece having an outer preformed surface of revolution, and in combination, fixed work support means having an arcuate "concave surface generally conforming with said outer preformed surface and extending circumferentially in contact therewith sufiiciently to position the workpiece radially, a grinding tool applicable internally of said workpiece to refine said inner surface, rotating end stop means abutting the workpiece preventing its axial movement in one direction, yieldably mounted roll means engageable against said outer surface holding the workpiece against said support means, means to urge the workpiece against said end stop means, means to rotate the workpiece in said support means, and means to retract the roll means from the workpiece after completion of a finished workpiece] [4. In an internal grinding machine for refining an inner surface of revolution of a workpiece, said workpiece having an outer preformed surface of revolution, and in combination, fixed work support means having an arcuate concave surface generally conforming with said outer preformed surface and with which said outer preformed surface is engageable, said support means extending circumferentially in contact with said outer surface sufficiently to position said workpiece radially, a grinding tool applicable internally to said workpiece to refine said inner surface, rotating end stop and workpiece drive means abutting the workpiece preventing its axial movement in one direction, roll means engageable against said outer surface holding the workpiece against said support means,

and means urging the workpiece against said drive means thereby rotating the workpiece in said support means] [5. In an internal grinding machine, for generating an inner surface of revolution of a workpiece, said workpiece having an outer preformed surface of revolution, and in combination, fixed work support means having an arcuate concave surface generally conforming with said outersaid support means and said end stop means, means to 9 rotate the workpiece in said support means and means to separate. :the'rolls after completion of a finished WorkpieceJf,

[6. In aninternal grinding machine for generating an inner surface of revolution of a workpiece, said workpiece, having ,an outer preformed surface of revolution, and in combination, fixed work support means having an arcuate concave surface generally conforming with said outer preformed surface and with which said outer preformed, surface is engageable, a grinding tool applicable internally of said workpieceto generate said inner surface, end stopmeans abutting the workpiece preventing its axial movementin one direction, a pair of skewed rolls ,engageable against, said outer surface holding the workpiece against said support means and said end stop means, means to rotate the workpiece in said support means, and means to separate the rolls after completion of a finished workpiece and then-to eject finished workpieces] [7," In an internalgrinding machine for generating an inner surface of revolution, ofa workpiece, said workpiece having anouter preformed surface of revolution, and in combination, fixed work support means having an arcuate concave surface generally conforming with said outer preformed surface and with which said outer preformed surface is engageable, a grinding tool applicable internally of said workpiece to generate said inner surface, end stop means abutting the workpiece preventing its axial movement in one direction, a pair of skewed rolls engageable against saidouter surface holding the Workpiece againstsaidsupport means and endstop means, and means to rotate at least one of said skewed rolls thereby rotating the workpiece in said support means] [8. In an internal grinding machineforgenerating an inner surface of revolution of a workpiece, said workpiece having an outer preformed surface of revolution, and in combination, fixed work support means having an arcuate concave surface generally conforming with said outer preformed surface and with which said outer preformed surface is engageable, a grinding tool applicable internally of said workpiece to generate said inner surface, a rotatable end stop abutting the workpiece preventing its axial movement in one direction, a pair of skewed rolls engageable against said outer surface holding the workpiece against said support and end stopmeans, and means to'drivesaid end 'stopthereby rotating said workpiece in said support] [9:"Inan internal grinding machine for refining an inner surface of revolution of a workpiece, said workpiece'having an .outer preformed surface of revolution, and in combination, rfixed work support means having an arcuate concave surface generally conforming with said outerpreformed 'surface and extending circumferentially in contact-therewith,'sufiiciently to bridge irregularities thereon=and to position the rotating workpiece radially, a grinding tool "applicable to said workpiece to refine .said inner surface, .a backplate abutting the workpiece, and

adapted 'to fix the'planeof its end surface, means to holdthe workpiece against said backplate, a pair of rolls engageable againsttsaid outer surface, and means to rotate said-rolls one at a diiferent peripheral speed than that ofthe other, said rolls thereby driving said workpiece and urging it against said support means] [10. In an internal grinding, machine for refining an inner surface ,of'revolution of a workpiece, said workpiece having an outer preformed surface of revolution,

and in combination, means to rotate the workpiece, fixedv work support means having an arcuate concave surface generally conforming with said outer preformed surface and extending circumferentially in contact therewith 'sufiiciently'to bridge irregularities thereonand to position therotating workpiece radially, a grinding tool applicable to said workpiece to refine said inner surface, rotating end stopmeans abutting the workpiece preventing its axial movement in one direction and a pair of skewed" rolls .engageable aga nst, said ,outerr workpiece against said support means said rolls being .urged together-rand against thewor'kpiece by balanced pressure means] [11. In an internal grinding machine for generatingan inner surface of revolution of a workpiece, said work:

piece having an outer preformed surface of revolution,

work support means. having conforming with said outer; which said outer preformed surface is engageable, a grinding tool applicablefinten.

and in combination, fixed an arcuate concave surface preformed surface and with nally of said workpieces to generate said inner surface,

a platen abutting the workpiece adapted to fix the plane of rotation thereof, roll means engageable against said outer surface holding the workpiece against said support,

means, non-reversible means urging said rollmeans against said workpiece and preventing movement of the rollmeans away from said support means, means to urge the workpiece against said platen, and means to rotate the workpiece in said support-means] E12. In'aninternal grinding machine for generating an inner surface of revolution of a workpiece,'sai'd workpiece having an outer preformed surface of'revo'lution, and in combination, fixed work-supportmeans with which said' outer preformed surface is applicable internally of said engageable, a grinding tool against 'said outer surface holding-'the-Workpiece against of the roll means away draw the roll means after-operation of-the replacement of afinishedworkpiece] {13. In an internal inner surfaces of revolutionchaving the-same diameter in a pluralityiof workpieces having outer preformed surfaces of revolution .of different'diameters, and in combination, a a grinding tool applicable internally of-said workpieces,

saidi-support means'] [14; In aninternal inner surfaces of revolution-having the same diameter in a plurality of workpieces having-outer preformed surfaces of :revolution of different diameters, and in combination,

tially equidist'ant'fromnhe line of contact 'of'said wheel,

end stop meansabutting one of a plurality of adjacent each said workpiece and preventing. movement of therroll.

means away from said support, means to urge =.the. work: pieces against the end surface v holding ,lhe. and, endstop means,

grinding machine for generating movement inone direction, roll means engageable against each of *saidouter surfaces holding the=.workpieces against said support, irreversible frictionmeans .urgingsaid-rollmeans against each said workpiece grinding machine for generating stop means, means to rotate the" 1 1 workpieces in said support means, and means to withdraw the roll means after operation of the wheel to permit replacement of finished workpieces] [15. In an internal grinding machine for generating an inner surface of revolution of a workpiece, said workpiece having an outer preformed surface of revolution and an end surface, and in combination,

forming with said outer preformed surface and extending circumferentially in contact therewith sufficiently to bridge irregularities thereon, said support means thereby fixing the rotating workpiece radially, a grinding tool applicable to said workpiece to generate said inner surface, rotatable end stop means abutting the workpiece preventing its axial movement in one direction, means to rotate the end stop means and thereby the workpiece, and pressure means having roll means engaging an end surface of said workpiece and holding it in frictional engagement with said end stop means, the axis of revolution of said roll means being displaced from piece, said pressure means thereby also urging said workpiece against said support] [16. In an internal grinding machine for refining an inner surface of revolution in a workpiece having a preformed outer surface of revolution, and in combination, a rotary tool applicable to said inner surface, a rotating platen adapted to fix the plane of an end surface of a workpiece in frictional contact with said platen and to drive said workpiece, support means having a stationary arcuate surface extending circumferentially in contact with said outer surface suificiently to fix the location of the workpiece in the plane of said platen, and roll means engageable with an end surface of the workpiece to hold it against said platen, the axis of revolution of said roll means being displaced from the axis of revolution of said workpiece, whereby the workpiece is urged against said support] [17. In an internal grinding machine for refining an inner surface of revolution of a workpiece, said workpiece having 'an outer preformed surface of revolution, and in combination, means to rotate the workpiece, fixed work support means having an arcuate concave surface generally conforming with said outer preformed surface and extending circumferentially in contact therewith sufiiciently to bridge irregularities rotating workpiece radially, a grinding tool applicable to said workpiece to refine said inner surface, a rotary backplate mounted with sufiicient radial play to allow it to be positioned radially by said workpiece, said backplate being adapted to position said workpiece axially and angularly, and pressure means independent of said backplate adapted to engage and to follow said workpiece, holding it against said support means and against said backplate] [18. In an internal grinding machine for generating an inner surface of revolution of a workpiece, said workpiece having an outer preformed surface of revolution and an end surface, and in combination, fixed work support means having an arcuate concave surface generally conforming with said outer preformed surface and extending circumferentially in contact therewith sufliciently to bridge irregularities thereon, said support means thereby fixing the rotating workpiece radially, a grinding tool applicable to said workpiece to generate said, inner surface, rotatable end stop means abutting the workpiece preventing its axial movement in one direction, means to rotate the end stop means and thereby the workpiece, androll means engaging an end surface of said workpiece and holding it in frictional engagement with said end stop means, the axis of revolution of said roll means forming an angle of less than 90 with the axis of said end stop means] "[19. In an internal grinding machine for generating an inner surface of revolution of a workpiece, said workpiece having an outer preformed surface or revolution and an end surface, and in combination, fixed work sup-,

the axis of revolution of said workthereon and to position the fixed work support means having an arcuate concave surface generally conport means having an arcuate concave surface generally said outer preformed surface and extending circumferentially in contact therewith sufficiently conforming with to bridge irregularities thereon, by fixing the rotating workpiece radially, a grinding tool applicable to said workpiece to generate said inner surface, rotatable end stop means abutting the workpiece preventing its axial movement in one direction, means to rotate the end stop means and thereby the workpiece, and roll means engaging an end surface of said workpiece and holding it in frictional engagement with said end stop means, the axis of revolution of said roll means forming an angle of less than with the axis of said end stop means, and means for rotating said roll means and said support means therethereby urging said workpiece against said support means] l arcuate concave surface substantially conforming with said' outer surface and extending circumferentially in contact therewith sufliciently to bridge irregularities therein and to fix the center of rotation of said workpiece, a backplate adapted to fix the plane of the end surface of a workpiece abutting said backplate, means for forcing said workpiece against said hackplate, means for rotating said workpiece, roll means and positioning means for moving said roll means into contact with said outer surface, said positioning means being adapted to exert only a comparatively light force when said roll means moves toward the workpiece and being adapted to resist with comparatively great force motion of said roll means away from said workpiece, thereby preventing said workpiece from being moved away from said support means by force exerted by said tool] [21. In an internal grinding machine for refining an inner surface of revolution of a workpiece, said workpiece having an outer preformed surface of revolution, and in combination, means to rotate the workpiece, fixed work support means having an arcuate concave surface generally conforming with said outer preformed surface and extending circumferentially in contact therewith sufficiently to bridge irregularities thereon and a grinding tool applicable to said workpiece to refine said inner surface, said support surface including a hole through which fluid may be forced to reduce the friction between said workpiece and said support] [22. In an internal grinding machine for refining an inner surface of revolution of a workpiece, said workpiece having an outer preformed surface of revolution, and in combination, work support means including a fixed support having an arcuate concave surface generally conforming with said outer preformed surface and extending circumferentially in contact therewith sufficiently to bridge irregularities thereon, said fixed support being comprised of non-magnetic material, rotatable end stop means abutting the workpiece, rotatable pressure roll means engageable against said workpiece to hold it against said support means, means connected to one of said rotatable parts to drive said workpiece and a permanent magnet connected to establish a magnetic circuit in said end stop means and through said wokpiece and pressure roll means thereby increasing the friction between said end stop means, workpiece and pressure roll means] 23. In an internal grinding machine for finish grinding the inner surface of a bore in a round workpiece and in combination, a work support including at least one shoe having a surface which is concave generally circumferentially of and in a plane normal to an average axis and arranged to receive and make sliding contact with a circumferential portion of an outer surface of revolution of a workpiece when it is rotated substantially on said axis while bridging irregularities thereon to support said workpiece radially, end stop means spaced from said shoe having work engaging elements circularly arranged around and in a plane substantiallymormal. tolsaid average. axis, said work engaging elements being capable ofiabutting circumferential portions of-one end of a, workpiece: to fix its endwise position while allowing said workpiece. to be supported radially by said shoe, a grinding tool capable of being inserted into the bore of a said workpiece and meansto insert said tool within the bore andto move it against its inner surface.

24. The combination as setforth i l-claim 23, including means to rotate a said workpiece .while it is in contact with said shoe and said end stop means.

25. The. combination, as set forth in claim 23 including pressure means operable to generate aforce-,upon ,said workpiece in a direction to hold it against said. end stop means. I

26". The combination as set forth in claim 23 including pressure means operable to generate a forceupon said workpiece in a direction to hold it against said shoe.

27. The combination as set forth in'claim 23 pressure meansindependenrof. said end stop means en- .gageable against and operable to'generate forces upon said workpiece in directionssuch as to hold it against both said .shoe and said end stopmeans, and means to rotate said workpiece in said position.

28. The .combination. as set forth. in claim 23 including yieldably mounted roll means engag'e'able 1 against said outer surface to hold the workpiece against saidshoe, means to. urge the workpiece againsnsaid, end stop means and means to rotate theworkpiece.

29. The combination as set. forth in claim 28 including means to retract theroll' means fron rthe workpiece after completion of a grinding operation.

30.. In the.combination.as-2set forth in clairn.23,.:said end. stop-1 means .being.rotatable,..rolbntteans engageable against said outer. surface. to hold thezworkpiecegagainst said shoe, :means. to. urgethe :workpiecesagainst the :end stop means, andmeans. to. drivethe endzstop means; to rotate. the workpiece.

31. The combination. as. set. forth; in;.claim 2%2-3 including apair of skewed. rolls .engageabl againstasaid' outer surface to holdthe workpiece :againstzbioth saidishoesand said. end stopameans. and. means. to. separate the; rolls-after completion of a grinding operation.

32. The combination as set forth in claim 31 including means to eject a finished workpiece after separtion of said rolls.

33. The combination as set forth in claim 31 including means to drive at least one of said skewed rolls to rotate the workpiece.

34. In the combination as set forth in claim 31, said end stop means being rotatable and means to drive said end stop means to rotate the workpiece.

35. The combination as set forth in claim 31 including balanced pressure means to urge said rolls toward each other and against the workpiece.

36. The combination as set forth in claim 23 including means to hold the workpiece against said end stop means, a pair of rolls engageable against said outer surface, and means to drive said rolls one at a different peripheral speed than the other to rotate the workpiece while urging it against the support shoe.

37. The combination as set forth in claim 23 including roll means engageable against said outer surface to hold the workpiece against said shoe, means to urge the roll means against the workpiece, and means to prevent movement of the roll means away from said workpiece during a grinding operation.

38. The combination as set forth in claim 37 including means to withdraw the roll means from the workpiece after completion of a grinding operation to permit replacement of the finished workpiece.

39. The combination as set forth in claim 23, said end stop means including a magnet operative upon a said workpiece in contact with said work engaging face to urge the workpiece against the end stop means.

including i .14, ..40 3,.In.antinternalugrinding machine for finish grinding; simultaneously the innezgsiirfacesfof bores in a 'pluralityof round workpieces and in combination, a work support including at least one shoe having a-surface which isuconcave generally circumferentially of and in .a plane normal to anaverage axis and arranged simultaneously to receive and make slidfng contact with circumferential portions of outer surfaces-of revolution of a said pluralitylof workpieces whenlthey are rotated incoaxial abutting relationship substantially o n.s,aid axis while bt' idgingirregularities thereon to support said workpieces radially, end stop mean spaced from said shoe .having work engaging elements. circularly arranged around and in aplanesubstantially normal to said average axis, said work engaging elements being capable of abutting. circumferential portions of one end of one of said workpieces to fix their endwise position while allowing them to. be. supported radially "by said shoe, agrinding tool having a radius smaller than. the average radius of said concave shoe surface and capable of being inserted into the bores of a said plurality of workpieces-and means to insert said tool within said bores and; against their inner surfaces. 41. The combination as set forth in claim 40includingmeans to rotate said plurality .of workpieces while .they are in contact with said shoe and in abutting relation to said endstop means.

'42.T he combination as set forth in claim 40 including pressuremeans operable to generate a force .upon said workpieces in a.direction to urge them toward. said end stop means.

("43. Ihe'combination asset forth in.claim-40 including pressure means operable to generate a forceupon said workpieces in a direction to urge them toward said shoe.

"44.The. combination. as setlforth in claim 40.in'cluding.roll means engageablegagainst each of said outer surfaces to hold .the workpieces against said shoe, and means to urge said roll means=against each said outer surface together. with means. to prevent .movement .of' the. roll means away from said workpiecesduring a grinding operation.

453"The combination as set.'forth in claim 44 includ- 'ng means to withdraw the roll meansafter operation"of the grinding tool to permit replacement of finished workpieces,

46. In an internal grinding machine for finish grinding an inner surface of a bore in a round workpiece and in combination, a spindle, a work support including at least one shoe having a surface which is concave generally circumferentially of and in a plane normal to the axis of said spindle and arranged to receive and make sliding contact with a circumferential portion of an outer surface of revolution of a workpiece when it is rotated substantially on said axis while bridging irregularities thereon to support said workpiece radially, a backplate mounted to rotate with said spindle having a work engaging face substantially normal to said spindle axis and in spaced relation with said shoe, said work engaging face being capable of abutting one end of a workpiece to fix its endwise position while allowing said workpiece to be supported radially by said shoe, a grinding tool having a radius smaller than the average radius of said concave shoe surface and capable of being inserted into the bore of a said workpiece and means to insert said tool within the bore against its inner surface.

47. The combination as set forth in claim 46 including means to drive the backplate to rotate the workpiece.

48. The combination as set forth in claim 46, said backplate being mounted with its axis of rotation eccentric to the axis of a said radially supported workpiece thereby to make sliding frictional contact with a said workpiece and in a position with respect to said shoe such that a force is exerted by said frictional contact to urge said workpiece against said shoe.

49. The combination as set forth in claim 48 includv1.5 ing means to drive the backplate to rotate the workpiece.

50. The combination as set forth in claim 46 including a pressure roll positioned to engage an end surface of a workpiece in the shoe to urge it into abutting engagement with said backplate.

51. The combination as set forth in claim 50, the axis of revolution of said roll being displaced from the axis of a said workpiece and in a position with respect to said shoe such that a frictional force is exerted by said roll to urge said workpiece also against said shoe.

52. The combination as set forth in claim 50, the axis of revolution of said roll forming an angle of less than 90 with the axis of said spindle.

53. The combination as set forth in claim 46, means to provide radial play in said spindle to allow it to center itself with the axis of rotation of a said workpiece.

54. The combination as set forth in claim 46, said shoe having an internal passage to said concave surface through which fluid may be forced to reduce friction between a workpiece and said shoe.

55. The combination asset forth in claim 46, said backplate including a magnet operative upon a said work} piece in contact with said work engaging face to urge the workpiece against the backplate.

56. The combination as set forth in claim 46, includ- 1 ing means to drive the backplate to rotate the workpiece,

said backplate including a magnet operative upon a said workpiece in contact with said work engaging face to urge the workpiece against the backplate.

57. The combination as set forth in claim 46, said backplate being mounted 'with its axis of rotation eccentric to the axis of a said radially supported workpiece thereby to make sliding frictional contact with a said workpiece and in a position with respect to said shoe such that a force is exerted by said frictional contact to urge said workpiece against said shoe, said backplate including a magnet operative upon a said workpiece in contact with said work engaging face to urge the workpiece against the backplate.

58. Method of finish grinding the inner surface of a bore in a round workpiece which comprises rotating the workpiece while supporting it radially over a continuous circumferential portion of its outer surface of revolution,

non-yieldingly supporting it in an endwise direction without exerting a centering effect and grinding the inner surface of the bore.

' 59. In the method as set forth in claim 58 the step of urging the workpiece against the direction of its said endwise support.

60. In the method as set forth in claim 58, the step of urging the workpiece against the direction of its said radial support.

61. Method of finish grinding the inner surface of a bore in a round workpiece which comprises rotating the workpiece non-yieldingly supporting it radially over a continuous circumferential portion of its outer surface of revolution while exerting an opposite yielding force against it, non-yieldingly supporting it in an endwise direction without exerting a centering effect while exerting an opposite yielding force against it, and grinding the inner surface of the bore.

62. The combination as set forth in claim 23, said work support also including a rotatable'roll and means to support said roll on a fixed axis and with the periphery of said roll in circumferential spaced relation concave surface of said shoe thereby to make contact with a said outer surface of a workpiece in contact with said shoe.

63. The combination as set forth in claim 62 and means to drive said roll to rotate the workpiece.

References Cited in the file of this patent or the original patent UNITED STATES PATENTS 2,027,627 Bloodet a1. Jan. 14, 1936 2,032,269 Einstein et a1 Feb. 25, 1936 2,047,055 Blood July 7, 1936 2,107,051 Briney Feb. 1, 1938 2,171,892 Richardson Sept. 5, 1939 2,243,371 Blood May 27, 1941 2,264,179 Johnson Nov. 25, 1941 2,440,148 Madison Apr. 20, 1948 2,478,562 Binns Aug. 9, 1949 2,478,607- Theler et a1. Aug. 9, 1949 2,635,395 Arms Apr. 21, 1953 to the said 

